<h1>Angular Router</h1>
<nav>
    <a routerLink="/crisis-center" routerLinkActive="active">Crisis Center</a>
    <a routerLink="/heroes" routerLinkActive="active">Heroes</a>
    <a routerLink="/admin" routerLinkActive="active">Admin</a>
    <a [routerLink]="[{ outlets: { popup: ['compose'] } }]">Contact</a>
</nav>
<!-- 在宿主视图中的RouterOutlet之后显示匹配的组件 -->
<router-outlet></router-outlet>
<router-outlet name="popup"></router-outlet>